In the proposed studies we will examine the relationship of the contact (Hageman factor) system and the development of provoked bronchospasm in patients with asthma and allergic and non-allergic bronchitis. Evidence has been obtained indicating that the contact system can be activated by allergic reactions both in vitro and in vivo. The proposed studies will clarify the relationship between allergic reactions and activation of the contact system employing recently development methods that are sufficiently sensitive to provide clear data. We will compare data on the activation of the contact (bradykinin-forming) system and levels of leukotriene C and D in bronchoalveolar lavage fluid. This will be performed because of the known stimulation of the arachidonate system by bradykinin. Other studies are directed toward understanding the pathogenesis of allergic and non-allergic bronchitis. Free elastase and oxidized alpha-1-PI have been found in lavage fluids from patients with bronchitis in preliminary studies. We will further explore the relationship of these to inflammatory pulmonary disease.